Fume devit?

**Mattypo** · 01-31-2015, 06:37 AM

Couldn't find much on the subject but I'm having some issues with some foggy matte looking glass after I fume gold over silver. Never had this problem with just silver before. It won't melt in and salt won't work so I'm not sure what the problem is. New propane tank too. Anyone have any ideas??

**Captain Glass** · 01-31-2015, 10:50 AM

Can you tell if the problem is on the inside of the tube or outside and what kind of torch are you using.

**hashcat** · 01-31-2015, 11:16 AM

i get this all the time too, just started fuming past few months

mines on the surface wherever the fume is exposed, gtt mirage

i can prevent it happening by getting the glass super hot and oxidized (think burning off haze with AP) or remove it later with a highly oxidized flame on my minitorch.

in my opinion is from reduction. now i dont know if this can be solved by fuming differently, working differently, or what?

**Mattypo** · 01-31-2015, 01:01 PM

It's on the outside. I sky down lines and the in the space where I don't lay lines this happenes. I don't use a reduction flame when I'm working in fume. I use an oxygen or neutral flame. I'm on a bravo.

**BORO** · 01-31-2015, 02:08 PM

Try the propane first. Espcially if that's the only new variable.

**hashcat** · 01-31-2015, 02:12 PM

still maybe try turning down the propane pressure a bit. i didnt think i was running reduction flames either but once i dropped the propane from 8psi to 5psi it helped a lot, but i still get it every now and then

staying tuned for more answers

**Mattypo** · 01-31-2015, 04:56 PM

I'm on a bravo 2.5 psi for propane, I run it around 3. It's only on the spots where I didn't lay clear lines. This shit is ruining everything I am trying to make. Only happens when I'm using gold. If I hit the gold with the flame would that cause this? I'm so frustrated over this....

**chicharrone** · 01-31-2015, 05:30 PM

its the glass moving when its almost stiff its not quite hot enough .That being said it has to burned back off in a oxidizing flame just like hashcat said.

**BORO** · 01-31-2015, 05:33 PM

I have had pieces come out like that.

First ones to sell. " Is that selective sandblasting?" ( it's not a bad thing , if you can controll it. )

Odorant additive , rust , bottom of a big holding tank , lots of bad propane possibilitys. Does your flame have the "yellow" spots in the fame ? Similar to the way dust burns in n the flame?

Do you fume your gold with the same flame you fume your silver with? Gold likes a pinned flame that's still pretty bright blue, but moving as slow as I can get it. I fume silver with a much bigger softer flame, much more see through blue ( still a pinned flame ) I get a sub par gold fume on the really soft flame for silver. Gold usually pours off with the right flame, makes it all super purple metallic.

Fwiw. I burn off ALL gold that's un encased on the outside. No matter if it's on silver, baked in hot , however you like it. It still burns off when the glass is hot enough to form with no stress. I also noticed in the first o.p. Pic , you twisted the tube? Twisted , cool tube will get that haze much easier.

The piece in this thread, is a good example of my gold on the outside. Only the gold under clear stayed intact.

http://www.talkglass.com/forum/showt...anny+lines+sir

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I was wondering what this bubbly moisture under my fume is? Seems to show up on the gold+silver.. I thought it was dusty tube? However it happened again last week on spanky clean tube. It's got me scratching my head. It shows up at the shaping stage, right almost at the end. I work hot and fast. I doubt it could be moisture. It's a dry balmy 72 inside the shop at 42degrees.

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The color pattern looks funny at first, but it's simple. Your just looking at each side of the spoon laid over one another.

**Mattypo** · 01-31-2015, 06:37 PM

I fume silver with a reduction flame I have no problem with silver, have good results. It's the gold on top of that i think is giving me the problem. I will keep at it and figure it out eventually

**Shattered Dreams** · 01-31-2015, 09:59 PM

ive been getting the same thing the last few time I fumed silver and then gold.
layed down a couple lines, but then I noticed some rough areas in the unencased spots.
I encased over it anyways but already knew its fucked.
seems like it traps a bunch of air bubbles as you go over it.
ive been thinking the silver is boiling from underneath the gold and leaving a rough texture.
I can get it to burn off, but don't usually want it to be burnt off there.

I haven't figured out what ive been doing that causes it to happen yet,
other than hitting those areas with a flame it doesnt like.
so ive just been trying to be careful and get it encased without the flame hitting it much.

**BORO** · 02-01-2015, 12:22 AM

^ I do burn off some of the extra fume on the inner wall of the blank. The heavy 02 flame on the fume . That is it I imagine. (+rep)

I was asked "where is the gold fume" on the yellow bub. Its the small orange spots on all the yellow sections. fume the yellow , dot it up , work like normal. All the gold under the clear dots stay , the rest burns off. The honey combs had gold added before the "dot up step" as well.

According to the owner , It earned that bub the title "Gold Finger".

LumpyHead, as far as the herbert arnold question. They fume amazing. I talked about it in the fume shots thread. ( page 19 post 373 )

I also went over some general h.a. basics in this thread...

http://www.talkglass.com/forum/showt...Herbert+arnold

I only know of one real thing I can't get a gtt to do , that a h.a. will. I can take super fumer color rod. Like any n.s. exotic for example. Put it in a slightly oxidizing flame on my h.a. and it stays a true black. Just like the rod. No fume. If I go reducing , it fumes out like every other brand of torch does it. I played with a new, low hours, phantom last week. No matter the regulator settings. No matter the knob settings , the exotic never stays black and smooth. Everything other than that can be done, and done well on any brand torch? (as far as I am aware ) I know I can work very delicate areas, add glass detail, and not melt what is already there. I imagine you can do that on a gtt as well.

I could not heat a COLD crack where it starts on a given piece of glass with my old cc torch. The crack spreads unless hot out of the kiln. With my h.a. The crack melts in 90+% of the time, not spreading . Even when its cold glass. It's the only other "how did it do that" factor I have found. I would not risk this on a worked piece. I have seen it fix clear dozens of times.

Someone on f.b. made a good analogy. Its kind of like ovens. The h.a. is like a oven on bake. It heats it even some how , all the way through. The gtt. Its like a broiler. Gives you a different, faster result, cooks it from the outside in. The outside gets soft first with a gtt.

(sorry for the thread jack)

**B-Rye-oNeR** · 02-01-2015, 06:09 AM

I feel like this happens from inconsistent heat base/ heating and cooling. And or too much metal on the fuming rod. I get it inside more than out, when doing IO fume/clear stringer . (This is my experience at least)

**chicharrone** · 02-01-2015, 06:29 AM

i make fume prodo spoons by the dozens i see what you are talking about every day .Your stretching or pulling or twisting when it not hot enough. Every spoon i make gets a divit polish because it almost always has it right under where the head is blown out. If its on the outside just burn it back off not a big deal. BoRo On your inside work are you using Asian Tube ?

**Captain Glass** · 02-01-2015, 02:53 PM

The reason I asked about if it was happening inside or out and on what kind of torch, was because while I do get it on the outside right where the neck and the head get blown out which just gets blasted away with an oxidizing flame. But I've had it happen on the inside and it has nothing to do with stretching or being to cold it happens when I use a certain flame setting and It seems to boil the gold and makes an ugly looking texture / effect.

**chicharrone** · 02-01-2015, 04:39 PM

I only use Pyrex and have never seen the inside divit.

**BORO** · 02-01-2015, 05:39 PM

Simax.

I did see the first time on some pre cut tube I was gifted. That tube could be any brand. ( was told s b a )

Just to avoid this issue, I used 38mm simax , right out of the case , super cleaned with simple green then a windex like product. Scrubbed with Kimble wipes.

It did not happen for weeks , then poof here it is again. The only real difference is I hit the inner fume with a oxygen flame to dial back the thickness of the fume layer. That's the variable I am going to eliminate next. No extra fire on the fume surface.

The inner devit. It looks just like condensation. Tiny round bubbles inside. Right between the fume and the glass.

**Captain Glass** · 02-01-2015, 06:18 PM

That's the inner devit I was talking about, it happens after I've laid down any designs on the inside and go back with a flame that is concentrated and hot. So when I go back over it I pretty much turn off the blue knob off. And if it happens before you lay your designs down the glass has a super hard time sticking where the devit is and it will normally either not stick at all or it will pull the fume off.

Idk if I'm explaining this correctly but I can picture it in my head from when it used to happen. But I've almost eliminated it entirely now.

**BORO** · 02-01-2015, 07:09 PM

^ great explanation . I agree. +1

**Captain Glass** · 02-01-2015, 08:28 PM

Thank you ! I was having such a hard time explaining it but I can literally see every step of it piece by piece and now know how to prevent it. It's not the same devit that the op was posting about which is easy to get rid of by just hitting it with an oxidized flame.